A far cheaper alternative to standard light meters and it works!

I have been a photographer for 10 plus years. I have always loved having the ability to take stunning photos and share them with the world. One piece of gear I have never really used in all this time was a light meter. Why? I could not tell you. Maybe it was because I was scared that It would add more steps to my workflow. Maybe I was intimidated by a new device that I just didn’t want to learn. Who knows why or even how I have been able to avoid light meters all these years but I have.

Lately, I have been working a lot more with studio strobes and have had some extra time indoors due to the cold weather we have in this area. So I decided maybe it was time I try a light meter. Most people would go for a normal handheld meter but for me, I went towards the App Store to see if any light meter apps existed. Guess what? They do. So I am here today to try out the Luxi For All Light Meter.

Luxi For All Incident Light Meter for Mobile Devices REVIEW


Luxi For All is a small plastic dome that slides on top of your mobile device’s front-facing camera. It works with a free app to turn your mobile device into a light meter. The Luxi app is available in the app store for iOS devices, but the Luxi For All is also compatible with Pocket Light Meter and a couple of additional third-party apps. According to the user manual, Luxi works by “diffusing the light entering the front-facing camera of your device in a way which allows the app to read the amount of light striking your photographic subject or scene.” It’s strongly recommended that Luxi be calibrated any time it is used with a new device since the camera hardware within your phone was not designed with Luxi in mind.

Luxi For All Incident Light Meter for Mobile Devices REVIEW

There are two modes within the Luxi app — one is spot-metering with no Luxi attached and the other is incident light readings when the clip is seated on the device. The spot-metering option ends up using the rear-facing camera and readings are less accurate than those taken with the Luxi clip. Luxi mode captures the lighting from the front-facing camera when the Luxi clip is installed. It will show you the Exposure Value and Luminance readings from the scene and provide you with settings to lock into your camera to ensure proper exposure.


I have to admit that at first, I was a little lost with this incredibly simple device. The Luxi clip seems like nothing except a piece of plastic, but as it turns out, it’s a very capable diffuser that helps the Luxi For App capture its readings. I ended up using an iPhone 11 Pro to take readings and then shot photos with my Canon EOS-R (45mm lens). The process in actuality is relatively simple. You place the Luxi over the front-facing camera and open the app. Then you set two of the exposure perimeters for your camera (F-stop, Time, or ISO). You want to set the options that are going to control the style of photo that you want to capture.

Luxi For All Incident Light Meter for Mobile Devices REVIEW

The manual uses the following example:

If you are shooting on film with an ISO value of 100 and you wish to control depth of field, you’ll want to lock FSTOP and ISO to your desired settings, and let LuxiTM suggest an appropriate TIME for you.

The app makes it really easy to lock the settings you want to keep in order to get the light reading you need. You simply tap the lock icon on the settings you want. When you tap and hold the setting you want, a menu will appear that will make it possible for you to change that setting.


So, even though I was slightly confused about how to operate this simple device when I unboxed it, it became clear very quickly. The manual is actually very helpful, too. As innovative as this device is, I have to admit that there were a few things that I would like to see improvements on.

Luxi For All Incident Light Meter for Mobile Devices REVIEW
Photo Taken with Canon EOS-R, 45mm lens — Light Reading Taken by Luxi

First, the app flips back and forth between the calibration screen and the front-facing camera viewing screen. There doesn’t appear to be any solution to this problem. After a quick look at reviews in the app store, there was a user that noted this issue back in 2014. So, it’s apparently a problem that has been happening since then. The app hasn’t been updated since August 2019 (more than 6 months at the time of this article being published) so I would hope that the developers would include something about controlling the ‘flip’ in a future update.

The second issue is and it’s a big one, that the Luxi clip doesn’t seem to create a solid seal with the newest iPhone 11 models. I think this might be because of the position of the camera in relation to the front-facing camera. Even though the clip is supposed to be ‘universal,’ there appear to be some adjustments that need to be made for newer devices.


The Luxi for All clip and app combination makes for a portable, affordable, convenient light meter. Even though there could be some improvements made to the system, I feel that Luxi For All is a very easy way to always have a light meter with you but I wouldn’t use it for professional photography work.

For more details, visit LuxiForAll, Facebook, and Twitter.